Remove helper traits

Now that JSRef<T> is gone, there is no need to have helper traits.

On components/script/*.rs:

    # Remove imports.
    /^ *use dom::[a-z]+::\{.*Helpers/ {
        s/\{(Raw[^L]|[^L][^a])[a-zA-Z]+Helpers, /\{/
        s/, (Raw[^L]|[^L][^a])[a-zA-Z]+Helpers([,}])/\2/g
        s/\{([a-zA-Z]+)\}/\1/
        /\{\}/d
        s/::self;$/;/
    }
    /^ *use dom::[a-z]+::\{?(Raw[^L]|[^L][^a])[a-zA-Z]+Helpers\}?;$/d

On components/script/dom/*.rs:

    # Ignore layout things.
    /^(pub )?(impl|trait).*Layout.* \{/,/^}$/ { P; D; }

    # Delete helpers traits.
    /^(pub )?trait ([^L][^ ]|L[^a])[^ ]+Helpers(<'a>)? \{$/,/^\}$/D

    # Patch private helpers.
    /^impl.*Private.*Helpers/,/^\}$/ {
        s/^impl<'a> Private([^L][^ ]|L[^a])[^ ]+Helpers(<'a>)? for &'a ([^ ]+) \{$/impl \3 {/
        /^ *(unsafe )?fn .*\(self.*[<&]'a/ {
            s/&'a /\&/g
            s/<'a, /</g
        }
        /^ *(unsafe )?fn /s/\(self([,)])/\(\&self\1/
    }

    # Patch public helpers.
    /^impl.*Helpers/,/^\}$/ {
        s/^impl(<'a>)? ([^L][^ ]|L[^a])[^ ]+Helpers(<'a>)? for (&'a )?([^ ]+) \{$/impl \5 {/
        /^ *(unsafe )?fn .*\(self.*[<&]'a/ {
            s/&'a /\&/g
            s/<'a, /</g
        }
        /^ *(unsafe )?fn .*\(&?self[,)]/s/(unsafe )?fn/pub &/
        /^ *pub (unsafe )?fn /s/\(self([,)])/\(\&self\1/
    }

The few error cases were then fixed by hand.

components/script/dom/webglrenderbuffer.rs

@@ -47,22 +47,17 @@ impl WebGLRenderbuffer {
     }
 }
 
-pub trait WebGLRenderbufferHelpers {
-    fn id(self) -> u32;
-    fn bind(self, target: u32);
-    fn delete(self);
-}
 
-impl<'a> WebGLRenderbufferHelpers for &'a WebGLRenderbuffer {
-    fn id(self) -> u32 {
+impl WebGLRenderbuffer {
+    pub fn id(&self) -> u32 {
         self.id
     }
 
-    fn bind(self, target: u32) {
+    pub fn bind(&self, target: u32) {
         self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::BindRenderbuffer(target, self.id))).unwrap();
     }
 
-    fn delete(self) {
+    pub fn delete(&self) {
         if !self.is_deleted.get() {
             self.is_deleted.set(true);
             self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteRenderbuffer(self.id))).unwrap();